Well, I am abit ahead of the release date. This tutorial is done on Ubuntu Lucid 10.04 beta and I would not expect there would be major changes in final release that could disrupt any instructions listed here.
Prerequsites

Ubuntu repository contains Ruby 1.9.1 package however this package suffers few bugs that doesn’t run some Gem packages. So I would highly RECOMMEND you to compile for yourself a instance of Ruby 1.9.1 from source. To compile Ruby from source, you need to install compilers and libraries headers.Continue reading →